The present disclosure relates to a positively chargeable single-layer electrophotographic photosensitive member, a process cartridge, and an image forming apparatus.
An electrophotographic photosensitive member is used in an electrophotographic image forming apparatus. In general, an electrophotographic photosensitive member includes a photosensitive layer. The photosensitive layer can contain a charge generating material, a charge transport material (such as a hole transport material or an electron transport material), and a resin for binding these materials (a binder resin). Alternatively, the photosensitive layer may contain a charge transport material and a charge generating material, so as to attain, by one layer, both charge generating and charge transporting functions. Such an electrophotographic photosensitive member is designated as a single-layer electrophotographic photosensitive member.
As the hole transport material of an electrophotographic photosensitive member, for example, a tris(4-styrylphenyl)amine derivative is known.